It is often necessary to surgically treat spinal deformities. Numerous systems for use in spinal correction and fixation have been disclosed. Although there are a number of factors which determine the system utilized in a given clinical situation, surgical approach, i.e. anterior, posterior, or lateral, significantly influences system selection. Posterior systems usually include one or more longitudinal rods placed generally parallel to the spinous process with various attachment devices connecting the rod and a selected component of the spine. These attachment devices include pedicle screws, plates, spinous process hooks, sublaminar hooks, and pedicle hooks.
With respect to the use of hooks, the hooks should be pressed firmly against the bone to properly transfer stress from the spine to the longitudinal rod. In order to accomplish correct seating of a pedicle hook, a section of the lamina is typically removed. However, anatomical considerations make removal of the appropriate section of laminar bone difficult to determine. Consequently, the seating of a pedicle hook can be a complex task.
Synthes USA of Paoli, Pa. offers a pedicle finder that has etched markings on its shaft to provide the surgeon with a visual guide for freehand resection of bone from the lamina after the pedicle has been located. Sofamor Danek, Inc. of Memphis, Tenn., offers a pedicle elevator that assists the implantation of a pedicle hook. The pedicle elevator is used only after a portion of the lamina is resected freehand based on anatomical landmarks. With freehand resection of the lamina, frequently the distance from the cut to the pedicle is either somewhat shorter or longer than the similar distance in the pedicle hook.
Thus, there exists a need for an improved device and method for precisely locating a pedicle and resecting a portion of a lamina so that a pedicle hook can be properly implanted.